One New Change, London, United Kingdom

A change for the better

Engineers and architects come together to design a sustainable mixed-use development

One New Change is a mixed-use development in the City of London. The scheme covers 51,000m2 over eight floors, with shops, restaurants and high-grade offices and has transformed this part of the City creating a dynamic social space in which to work and relax.

At ground-level, the public realm has been transformed, with a series of shopping arcades forming a natural extension to the streetscape and reopening lost pedestrian routes. The public realm has been extended six floors upwards, with a public roof terrace offering views of St Paul's Cathedral.

Developing a giant structure next to St Paul's was a major challenge and represents a significant achievement. Nicknamed the stealth bomber because its amorphous form does not detract from views of the Cathedral, the energy and services strategy was key to the scheme's success, with evidence of plant minimised and compliance with the Mayor of London's Energy Strategy exceeded.

One New Change redefines engineering thinking and the way carbon savings can be delivered. The solution features one of the most sophisticated and innovative commercial ground source heat pump systems in Europe, comprising 196 active energy piles built into the foundations and one pair of open loop boreholes reaching 200m down to the aquifer. Heat pumps are arranged to allow flexibility to match the differing load profiles of the office and retail areas and provide heat recovery.

A specially developed control system maximises energy and carbon savings from the ground source energy system, enabling it to heat and cool different parts of the building simultaneously. It combines external temperature measurements and weather forecasts with information on the heating and cooling loads of the previous day and the efficiencies of the conventional systems, to optimise the energy system and maximise savings.

The energy and services solution brings One New Change significantly under regulatory levels for carbon emissions and saves approximately 900MWh of energy, 900 tonnes of carbon and £300,000 on energy bills a year. These savings arise from the use of the ground water, the thermal mass of the foundations and the optimisation of energy consuming systems. These supplement high-efficiency condensing boilers and chillers and meet 40% of the total heating and cooling loads.